Sensors connect to the hub, and the hub connects to the WiFi.
I asked this question (about running 2 hubs simultaneously) in the launch thread, and she initially said yes, then updated the answer to say not at this time.
Depending on the distance between them, you might be able to set the hub up at the far end of the house closest to the pole barn and cover both.
They do plan to allow you to have 2 separate systems/locations on the same account eventually, but currently you’d have to set up 2 different accounts…and what you really want is 2 hubs on the same account/subscription anyway. That will probably take a while to implement.